Draw distance through environment mapping

This is a discussion on Draw distance through environment mapping within the Game Programming forums, part of the General Programming Boards category; I was just playing GTA:San Andreas and noticed something odd in the background.
The edges of some of the polies ...

Draw distance through environment mapping

I was just playing GTA:San Andreas and noticed something odd in the background.

The edges of some of the polies at certain distances became blurred which later proved to be some type of post-processing filter applied to them. However, it gave me and idea.

We all know what cubic environment mapping is. Using that concept wouldn't it be possible to draw the most distant portions of a scene onto a cubic environment map texture and then texture the skybox/skydome using that. You would start with the sky texture and then blend in the environment texture like distant terrain, buildings ,etc. Then you would use that texture to texture the final skybox/skydome. What this means is that only the local environment is pure 3D which means you may be able to get away with a lot more polies close up than before.

I'm not sure how it would look without attempting it but I would like to hear some comments.

The edges of some of the polies at certain distances became blurred which later proved to be some type of post-processing filter applied to them

I think they used fog with full alpha for that.

I saw a project attempt what you suggest, but I don't remember if they ever succeeded. I know one of the problems they came into was noticable hitches when you walked across sector boundaries in their enviroment (I think they were using a quad tree).

Now that I think about it, maybe that's how some games show terrain at extremely long distances? Oblivion for example.